Jack.



G G. MORRISON.

- JACK.

APPLICATION FILED PEBJO, 1913.

Patented Mar. 30, 1915.

m WA 6 d 2 THE NORRIS PETERS CO.. FHOTO-LITHO.. WASHINGTON D. L

CHARLES e. MORRISON, OF smear BEND, KANSAS.

JACK.

ll,ll33,39"1.

Specification of Letters Patent. 7

Patented Mar. 30", T915.

Application filed February 10, 1913. Serial No. 747,328.

To aZZ whom it may concern Be it known that T, CHARLns G. MoRnIsoN,

such as employed in erecting reinforcedconcrete bins, and has for its object to produce a ack by whichthe work of raising moving forms is facilitated, and which can be operated easily and is of simple, strong, durable and compact construction.

With this general object in viewthe in vention consists inccertain novel andpecul.- iar features of construction and organization as hereinafter described and claimed; and in order that it may be fully understood reference is to be had to the accompanying drawing, in which Figure 1, is a central vertical sectlon of a jack embodying my invention, applied in operative position to a vertical rod such as used for reinforcing concrete Walls. Fig. 2, is a reduced section on the line IIII of Fig. 1. Fig. 3, is a section on the line TIT III of Fig. 1.

In the said drawing, 1 is a foot block provided with a threaded recess 2 in its upper end and with an upwardly tapering or conical bore or passage 3, extending from its underside to said recess, and communicating with the same centrally thereof; and at opposite sides of the bore or passage, the foot block is formed with channels 4 and with vertical slots 5 registering with the channels.

6 are jaws which fit slidingly in the channels 4 of the block and are provided at their inner faces with downwardly-disposed teeth 7 and with handles 8 projecting outwardly through slots 5.

The base plate 9, provided with a central opening 10, underlies block 1 and is secured thereto by cap screws 11, one only appearmg.

12 is a stand pipe secured at its lower end in recess 2 and at its upper'end in a collar 13. The collar is provided with a radially projecting arm 14? through which extends a pivot bolt 15 clamped to the arm by nuts 16 and 17 An'internally threaded collar consists of two halves l8 normally resting on collar 13 and provided with lugs 19 in different vertical planes, and said lugs terminate in superposed perforated bosses 20, fitting pivotally on pivot bolt 15 and retained thereon by a spring cotter 21, a washer 22 being interposed between the cotter and the topmost boss. At'the opposite side of the collar from pivot bolt 15, each half of the collar is provided with a handle 23 and with perforated bosses 24 adapted to occupy superposed relations when the halves of the collar are closed together, and to se cure said halves in such closed relation, a removable pin 25 extends through said bosses 24L.

26 is a tubular worm rod extending down through and engaging the threaded collar described, and loosely into the stand pipe 12. The upper end of said tubular worm rod is enlarged at 27 to retain upon said rod a collar 28, and shrunk or otherwise secured upon said rod so as to form ineffect an external enlargement thereof, is a collar 29, and formed in the last-named collar are radial openings 30, into which a lever (not shown), may be inserted for the purpose of imparting turning movement to the worm ro It is customary in the erection of concrete bins to employ a number of jacks, and to fit each jack over a reinforcing pipe or rod, such as 31, projecting beyond the upper end of the wall, the form being supported in the usual or any preferred manner on the customary yokes (not shown) mounted on the upper ends of the jacks. Assuming this arrangement of parts, it will be seen that gravity holds the jaws 6 in engagement with the rod 31 and to raise the form (not shown) a lever is inserted in one of the holes 30 and the worm rod turned to cause it to move upward, the rod 31 sustaining the load tube thus imposed upon it through the instrumentality of the jaws. The same operation is then repeated with each jack so that the level of the form being elevated shall be maintained, and then the operations described are repeated again and again until the forms are raised to the required height. The operator then Withdraws the pin 25 of one of the jacks and swings the halves of the internally threaded collar of such jack apart and thereby permits the threaded rod to drop down to its initial position, as shown in Fig. 1, the load, viz. the form, he-

mg carried by the other acks. As soon one of the jacks is thus relieved of its part of the load of the form, the operator can slide the entire jack upward on rod 31 until 5 the upper end of the jack again engages the form, andas the jack is released the toothed jaws automatically reengage the rod 31 and hold the jack in its adjusted position. The

other jacks are then successively handled in the manner described, so that eventually all of the jacks are adjusted to cooperate in supporting the form in its elevated position,

" and then the work of increasing the height rods of different thickness.

While I have illustrated and described the appliance as for use chiefly in the erection o concrete walls, it is obvious that it is adapted for practical use i Other connections and it is to be understood that I reserve the right to makeall changes falling thus at difierent points of adjustment grip Within the spirit and scope of the invention as defined by the appended claims.

I claim; v c- 1. The combination with a rod, a block fitting on the rod and having upwardly -tapering internal channels at opposite sides of the rod and slots communicating with said channels, a pair of upwardly-tapering toothed jaws fitting slidingly in said channels and adapted togrip said rod and thereby support the' foot block, a screw, and means supported by the foot-block engaging the screw to cause the same to move vertically when turned.

2. In a jack, a foot-block provided with an upwardly-tapering bore and slots coinmunicating with said bore and upwardlytapering jaws fitting in the said bore and adapted for vertical adjustment therein and provided with handles extending through said slots.

In testimony whereof I afiix my signature in presence of two witnesses.

CHARLES G. MORRISON.

Witnesses HELEN C. Rooms, G. Y. THORBE.

- 7 Copies of this patent may be obtained for five cents each, by addressing the commissioner of Patents.

7 4 i Washington, D. G," 

